Pliers, specifically snap-ring pliers are well known in the art. Snap-rings can be either “internal” or “external.” In their neutral state, internal snap-rings are generally disposed in a slightly open-loop configuration. They may be used to retain a part within a cylinder, for example, retaining a bearing in a shaft. To install an internal snap-ring the open-loop end is closed to decrease the diameter to fit within the cylinder. The snap-ring is then allowed to open within the cylinder, ideally within a groove. On the other hand, external snap-rings may be used to retain an object on the external side of a shaft, for example, gears or pulleys on a shaft. External snap-rings are generally disposed in a closed-loop configuration. The closed-loop may be spread open to permit the external snap-ring to fit over a shaft, then once in place, the external snap-ring may be released, preferably in a groove about the shaft, to retain the object on the shaft.
Generally, there are internal snap-ring pliers used to install internal snap-rings and external snap-ring pliers to install external snap-rings. Internal snap-ring pliers may consist of a pair of handles which cross at a pivot pin and with a tip at the snap-ring interface end. The crossing configuration allows a closing action of the handles to translate into a closing action of the tips, thus a closing of the open-loop of the internal snap-ring. External snap-ring pliers may consist of a pair of handles connected at a pivot point but do not cross at the pivot point. This configuration allows a closing action of the handles to translate into an opening of the tips, thus spreading the external snap-ring.
Additionally, there are internal/external snap-ring pliers which allow a user to switch between an orientation for use with internal snap-rings and an orientation for use with an external snap-ring. Some switchable devices provide a first handle with a pivot pin affixed to it and a second handle with a V-shape track in which the first handle pin travels within. However, in some orientations during use, one of the handles will be displaced relative to the other due to the orientation of the pin and the groove and the spring force exhibited by a biased snap-ring. This will either twist the snap-ring, making alignment with the groove more difficult, or cause the pliers to disengage from one end of the snap-ring entirely. Accordingly, the art of snap-ring pliers could benefit from a more reliably engaged device capable of easily switching from an internal to an external snap-ring pliers and vice versa.